Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Operating Activities
Net income	$ 30,320	$ 24,013
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	3,099	7,537
Depreciation and amortization	6,589	5,853
Net amortization of securities	1,618	1,559
Securities gains, net	(1,050)	(7)
Gains on sales of loans, net	(6,460)	(3,101)
Decrease in FDIC indemnification asset	60	0
Bargain purchase gain on acquisition	(2,754)	0
Deferred income tax provision (benefit)	1,880	(355)
Proceeds from sales of loans held for sale	378,255	242,755
Purchases and originations of loans held for sale	(388,370)	(195,964)
Originations and sales of mortgage servicing rights, net	(4,478)	(3,480)
Net decrease in other assets	3,940	29,455
Net increase (decrease) in other liabilities	10,674	(9,728)
Other operating activities, net	2,993	1,480
Net cash provided by operating activities	36,316	100,017
Investing Activities
Proceeds from calls and maturities of securities held to maturity	5,699	30,806
Proceeds from calls and maturities of securities available for sale	234,155	147,958
Purchases of securities available for sale	(374,785)	(283,517)
Net decrease in federal funds sold and securities purchased under reverse repurchase agreements	2,957	10,047
Net decrease in loans	74,593	68,952
Purchases of premises and equipment	(6,909)	(2,487)
Proceeds from sales of premises and equipment	0	374
Proceeds from sales of other real estate	10,039	15,399
Net cash received in business combination	78,151	0
Net cash provided by (used in) investing activities	23,900	(12,468)
Financing Activities
Net increase in deposits	315,587	381,707
Net decrease in federal funds purchased and securities sold under repurchase agreements	(349,622)	(149,219)
Net increase (decrease) in short-term borrowings	74	(274,385)
Common stock dividends	(14,900)	(14,866)
Common stock issued-net, long-term incentive plans	(1,154)	(219)
Excess tax benefit from stock-based compensation arrangements	674	976
Net cash used in financing activities	(49,341)	(56,006)
Increase in cash and cash equivalents	10,875	31,543
Cash and cash equivalents at beginning of period	202,625	161,544
Cash and cash equivalents at end of period	$ 213,500	$ 193,087